This statistic depicts the average total length of stay at U.S. nursing homes in 2014 and 2015, by status of ownership. In 2015, the average length of stay stood at 307 days at government owned nursing homes.

According to a 2021 survey, the majority of respondents in Canada said their loved ones stayed (currently or within the past year) in long-term care for less than three years. This statistic presents the length of stay of those who were currently in long-term care or were within the past year as reported by their loved ones in Canada as of 2021.

This statistic shows the leading 15 nursing home chains in the United States based on number of staffed beds in 2015. Ensign Group based in Mission Viejo, California had 13,803 staffed beds nationwide as of year-end 2015. In that year Genesis HealthCare had the most nursing homes among the leading nursing home chains in the U.S. with 419 such establishments. In 2015, the average length of stay at for-profit nursing homes was 172 days, compared to 307 days at government owned nursing homes.

The average number of years care home residents aged 65 years and over are expected to live beyond their current age in England and Wales. Classified as Experimental Statistics.

The percentage of long stay care home residents by length of their stay, as well as mean and median lengths of stay

The UK has an ageing population – for the Residential Nursing Care industry, this is an opportunity for growth with demand for more beds expanding. Homes have upped their average weekly fees, contributing to revenue. High inflation over the two years through 2023-24 has raised fees further. However, state involvement has limited growth, which has kept care fees artificially low for many nursing home residents. Residential nursing care revenue is anticipated to remain stable at £9.3 billion over the five years through 2024-25, including revenue growth of 3% in 2024-25. Weak government funding and wage cost pressures caused by the rising National Living Wage (which will increase to £12.21 in April 2025) have constrained profitability. Labour supply shortages caused by high turnover rates have been of particular concern. According to Skills For Care, the job vacancy rate in 2023-24 in the adult care sector was 8.3%, way above the average rate in the UK economy. That being said, the vacancy rate is declining thanks mainly to a government-driven recruitment drive to attract overseas workers, which has been helped by reducing visa requirements. Rising real household disposable income had supported more self-funded residents, aiding residential nursing care. However, data from the ONS revealed the percentage of self-funded residents fell from 36.7% in 2019-20 to 34.9% over the year through February 2022. In the year through February 2023, this has risen again to 37% of the 372,035 care home residents. Families are still struggling with the rising cost of living, reducing the number of people able to afford private care home costs, which has somewhat constrained revenue growth. Over the five years through 2029-30, residential and nursing care revenue is estimated to expand at a compound annual rate of 4.1% to £11.4 billion. Robust demand from an ageing population will support industry growth. However, plans for adult social care reforms are to be released in two stages (the first in 2026 and the second in 2028), which has caused greater uncertainty for the sector's future. Staff shortage concerns will continue to plague nursing care.

Number of council-supported permanent admissions of adults aged 65 and over to residential and nursing care divided by the size of the adult population (aged 65 and over) in the area multiplied by 100,000. People counted as a permanent admission include: Residents where the local authority makes any contribution to the costs of care, no matter how trivial the amount and irrespective of how the balance of these costs are metSupported residents in: Local authority-staffed care homes for residential careIndependent sector care homes for residential careRegistered care homes for nursing careResidential or nursing care which is of a permanent nature and where the intention is that the spell of care should not be ended by a set date. For people classified as permanent residents, the care home would be regarded as their normal place of residence. Where a person who is normally resident in a care home is temporarily absent at 31 March (e.g. through temporary hospitalisation) and the local authority is still providing financial support for that placement, the person should be included in the numerator. Trial periods in residential or nursing care homes where the intention is that the stay will become permanent should be counted as permanent. Whether a resident or admission is counted as permanent or temporary depends on the intention of the placement at the time of admission. The transition from ASC-CAR to SALT resulted in a change to which admissions were captured by this measure, and a change to the measure definition. 12-week disregards and full cost clients are now included, whereas previously they were excluded from the measure. Furthermore, whilst ASC-CAR recorded the number of people who were admitted to residential or nursing care during the year, the relevant SALT tables record the number of people for whom residential/nursing care was planned as a sequel to a request for support, a review, or short-term support to maximise independence Only covers people receiving partly or wholly supported care from their Local Authority and not wholly private, self-funded care. Data source: SALT. Data is Powered by LG Inform Plus and automatically checked for new data on the 3rd of each month.

In the United States, one in four patients were enrolled a total of 5 days or less in hospice before they passed away*. Yet one in ten received care for more than 275 days across their lifetime. Hospice care involves caring for those who are terminally ill. Such care usually does not include treatment but focuses instead on making the end of life as comfortable as possible. Hospice teams can include nurses, home health aides, social workers and physicians. Hospice providers Hospice care can be provided at the patient’s home or in a facility, such as a nursing home, assisted living, hospital or hospice care center. In 2022, there were around 5,899 Medicare certified hospices in the United States. The large majority of theses are freestanding independent hospices, while a much smaller portion are part of a hospital system or part of a home health agency. Hospice patients In 2022, there were around 1.72 million hospice patients in the U.S. Female Medicare beneficiaries were more likely than male to use hospice services. Expectedly, older adults (over 84 years) were more likely to be a hospice patient than younger peers. The most common diagnoses were neurological and cancer

Independent living can become challenging for people experiencing cognitive decline. With reduced functioning and greater care needs, many people with dementia (PWD) may need to move to another home with better safety features, move to live closer to or with relatives who can provide care, or enter a nursing home. Housing plays a key role in supporting quality of life for both PWD and their caregivers, so the ability to move when needed is crucial for their well-being. Yet the substantial costs of moving, housing, and care mean that PWD with limited financial resources may be unable to afford moving, exacerbating inequalities between more and less advantaged PWD. Emerging qualitative research considers the housing choices of PWD and their caregivers, yet little is known on a broader scale about the housing transitions PWD actually make over the course of cognitive decline. Prior quantitative research focuses specifically on nursing home admissions; questions remain about how often PWD move to another home or move in with relatives. This study investigates socioeconomic and racial/ethnic disparities in the timing and type of housing transitions among PWD in the United States, using Health and Retirement study data from 2002 through 2016. We find that over half of PWD move in the years around dementia onset (28% move once, and 28% move twice or more) while 44% remain in place. Examining various types of moves, 35% move to another home, 32% move into nursing homes, and 11% move in with relatives. We find disparities by educational attainment and race/ethnicity: more advantaged PWD are more likely to move to another home and more likely to enter a nursing home than less advantaged groups. This highlights the importance of providing support for PWD and their families to transition into different living arrangements as their housing needs change.

Here is a statistic that proposes to discover the average length of stay of residents who left nursing homes for dependent elderly (EHPAD) in France in 2015, by category of establishment. In that year, residents discharged from a non-hospital public nursing home stayed on average two years and ten months in such a facility. In all, the average length of stay of EHPAD residents was approximately two and a half years.

In view of the ageing population, the demand for care services is continuously increasing. Over the past five years, this development has contributed to an average growth in turnover of 1.5% per year. Vaccinations and compliance with social distancing and hygiene rules have reduced the risk of death in care homes during the coronavirus pandemic. As a result, the number of people moving from home to residential care has risen again. The development of energy prices, inflation and rising staff costs, which were insufficiently refinanced by the care insurance funds, had a negative impact on the earnings situation in 2022 and 2023. As a result of a significant delay in refinancing costs and falling capacity utilisation due to the shortage of nursing staff, many care facilities found themselves in financial difficulties in 2023, leading to an increase in the number of insolvencies.Revenue is expected to grow by 1.4% in 2024 and thus amount to 60.2 billion euros. The cost increases, which cannot be fully refinanced, and the worsening staff shortage are also likely to lead to occupancy freezes and capacity cuts in the current year. The high payment arrears of the social welfare offices and the long waiting time of the facilities for payments from the local social welfare organisations are affecting liquidity and leading to a higher risk of insolvency, as services are being provided that are only partially financed. In order to avoid getting into financial difficulties, the facilities pass on most of the additional costs to the residents. Despite the current surcharges to limit the personal contribution of care home residents and the planned dynamisation of benefit rates, personal contributions are likely to continue to rise in the coming years. More and more people will probably no longer be able to pay the rising co-payments and will be dependent on social assistance.In the coming years, demographic change is likely to have a negative impact on care service providers from two sides. The ageing population will continue to increase the demand for care services. At the same time, the worsening shortage of skilled labour means that care capacities will not grow to the same extent. In order to guarantee the provision of care, it will also be necessary to utilise financial and human resources as efficiently as possible. New technologies can help to relieve the burden on carers in their work. By 2029, turnover in the care sector is expected to increase by an average of 3.9% per year, meaning that it is likely to reach 72.9 billion euros in 2029.

BackgroundMedicare Advantage (MA) and Medicare fee-for-service (FFS) plans have different financial incentives. Medicare pays predetermined rates per beneficiary to MA plans for providing care throughout the year, while providers serving FFS patients are reimbursed per utilization event. It is unknown how these incentives affect post-acute care in skilled nursing facilities (SNFs). The objective of this study was to examine differences in rehabilitation service use, length of stay, and outcomes for patients following hip fracture between FFS and MA enrollees.Methods and findingsThis was a retrospective cohort study to examine differences in health service utilization and outcomes between FFS and MA patients in SNFs following hip fracture hospitalization during the period January 1, 2011, to June 30, 2015, and followed up until December 31, 2015. We linked the Master Beneficiary Summary File, Medicare Provider and Analysis Review data, Healthcare Effectiveness Data and Information Set data, the Minimum Data Set, and the American Community Survey. The 6 primary outcomes of interest in this study included 2 process measures and 4 patient-centered outcomes. Process measures included length of stay in the SNF and average rehabilitation therapy minutes (physical and occupational therapy) received per day. Patient-centered outcomes included 30-day hospital readmission, changes in functional status as measured by the 28-point late loss MDS-ADL scale, likelihood of becoming a long-term resident, and successful discharge to the community. Successful discharge from a SNF was defined as being discharged to the community within 100 days of SNF admission and remaining alive in the community without being institutionalized in any acute or post-acute setting for at least 30 days. We analyzed 211,296 FFS and 75,554 MA patients with hip fracture admitted directly to a SNF following an index hospitalization who had not been in a nursing facility or hospital in the preceding year. We used inverse probability of treatment weighting (IPTW) and nursing facility fixed effects regression models to compare treatments and outcomes between MA and FFS patients. MA patients were younger and less cognitively impaired upon SNF admission than FFS patients. After applying IPTW, demographic and clinical characteristics of MA patients were comparable with those of FFS patients. After adjusting for risk factors using IPTW-weighted fixed effects regression models, MA patients spent 5.1 (95% CI -5.4 to -4.8) fewer days in the SNF and received 463 (95% CI to -483.2 to -442.4) fewer minutes of total rehabilitation therapy during the first 40 days following SNF admission, i.e., 12.1 (95% CI -12.7 to -11.4) fewer minutes of rehabilitation therapy per day compared to FFS patients. In addition, MA patients had a 1.2 percentage point (95% CI -1.5 to -1.1) lower 30-day readmission rate, 0.6 percentage point (95% CI -0.8 to -0.3) lower rate of becoming a long-stay resident, and a 3.2 percentage point (95% CI 2.7 to 3.7) higher rate of successful discharge to the community compared to FFS patients. The major limitation of this study was that we only adjusted for observed differences to address selection bias between FFS and MA patients with hip fracture. Therefore, results may not be generalizable to other conditions requiring extensive rehabilitation.ConclusionsCompared to FFS patients, MA patients had a shorter course of rehabilitation but were more likely to be discharged to the community successfully and were less likely to experience a 30-day hospital readmission. Longer lengths of stay may not translate into better outcomes in the case of hip fracture patients in SNFs.

The mean and median age of long stay residents, as well as at the time of admission and discharge, by main client group.

How many people live in nursing homes? As of 2024, there were around 1.2 million residents in nursing homes across the United States. The states with the highest numbers of residents in certified nursing facilities were, by far, California and New York, with over 99,000 and 98,000 residents, respectively. On the other hand, Alaska had the lowest number of nursing home residents. Occupancy rates and recovery The COVID-19 pandemic significantly impacted nursing home occupancy rates nationwide. Prior to the pandemic, the median occupancy rate for skilled nursing facilities hovered around 80 percent. However, this figure plummeted to 67 percent by 2021. As of July 2024, occupancy rates for certified nursing homes have begun to recover, reaching 77 percent. This gradual increase suggests a slow but steady return to pre-pandemic levels. Quality concerns and financial penalties Despite the crucial role nursing homes play, quality issues persist in some facilities. In 2024, Aspen Point Health and Rehabilitation in Missouri faced 208 substantiated complaints, the highest number nationwide. Financial penalties for serious violations can be severe, as evidenced by the 1.41 million U.S. dollar fine imposed on Siesta Key Health And Rehabilitation Center in Florida over a three-year period. These cases underscore the ongoing challenges in maintaining high standards of care across the industry.

The increase in the number of people in need of care in Germany has had a positive impact on the outpatient care sector in recent years. Since 2020, turnover has grown by an average of 2.4% per year. The high demand can be explained by the extraordinary popularity of outpatient care. For many people, it is the preferred form of care in old age over nursing and retirement homes. Sales growth was therefore characterised in particular by an increase in the number of customers cared for and the resulting expansion in business activities.The poor earnings situation in recent years was due, among other things, to the increased personnel costs resulting from the introduction of the pay scale regulation in September 2022, which were insufficiently refinanced by the care insurance funds. Other cost drivers for care services, which often travel long distances in their cars, were the high energy and fuel prices. Many were also struggling to refinance previous cost increases in 2023. The high cost increases and lack of staff have a negative impact on profit margins and increase the risk of insolvency.In 2025, turnover in the sector is expected to reach 30.3 billion euros, which corresponds to an increase of 2.9% compared to the previous year. Despite the stable turnover, an increase in operating costs is having a negative impact on companies' earnings. In order to alleviate the shortage of nursing staff, a wage increase for nursing assistants, qualified nursing assistants and skilled nursing staff has been in place since January 2024. However, refinancing the increases in personnel costs remains a challenge for industry players. The increases in budget benefits provided for by the Care Support and Relief Act (PUEG) are unlikely to be sufficient to cover the additional costs, which are therefore likely to be refinanced primarily through price increases. Another problem is the fact that the funding organisations regularly do not refinance the additional costs immediately, citing the terms of existing contracts. The inadequately refinanced personnel and material costs will result in many companies employing fewer staff and offering fewer care services. The rising number of people in need of care in Germany and the great popularity of outpatient care services will keep demand at a high level in the coming years and lead to numerous new start-ups. Accordingly, IBISWorld anticipates average annual growth of 4.6%, with industry turnover of 37.9 billion euros expected in 2030. However, staff shortages are likely to lead to reduced capacity utilisation and continue to represent a significant obstacle to growth.

IntroductionA considerable percentage of daily emergency calls are for nursing home residents. With the ageing of the overall European population, an increase in emergency calls and interventions in nursing homes (NH) is to be expected. A proportion of these interventions and hospital transfers may be preventable and could be considered as inappropriate by prehospital emergency medical personnel. The study aimed to understand Belgian emergency physicians’ and emergency nurses’ perspectives on emergency calls and interventions in NHs and investigate factors contributing to their perception of inappropriateness.MethodsAn exploratory non-interventional prospective study was conducted in Belgium among emergency physicians and emergency nurses, currently working in prehospital emergency medicine. Electronic questionnaires were sent out in September, October and November 2023. Descriptive statistics were used to analyze the overall results, as well as to compare the answers between emergency physicians and emergency nurses about certain topics.ResultsA total of 114 emergency physicians and 78 nurses responded to the survey. The mean age was 38 years with a mean working experience of 10 years in prehospital healthcare. Nursing home staff were perceived as understaffed and lacking in competence, with an impact on patient care especially during nights and weekends. General practitioners were perceived as insufficiently involved in the patient’s care, as well as often unavailable in times of need, leading to activation of Emergency Medical Services (EMS) and transfers of nursing home residents to the Emergency Department (ED). Advance directives were almost never available at EMS interventions and transfers were often not in accordance with the patient’s wishes. Palliative care and pain treatment were perceived as insufficient. Emergency physicians and nurses felt mostly disappointed and frustrated. Additionally, differences in perception were noted between emergency physicians and nurses regarding certain topics. Emergency nurses were more convinced that the nursing home physician should be available 24/7 and that transfers could be avoided if nursing home staff had more authority regarding medical interventions. Emergency nurses were also more under the impression that pain management was inadequate, and emergency physicians were more afraid of the medical implications of doing too little during interventions than emergency nurses. Suggestions to reduce the number of EMS interventions were more general practitioner involvement (82%), better nursing home staff education/competences (77%), more nursing home staff (67%), mobile palliative care support teams (65%) and mobile geriatric nursing intervention teams (52%).Discussion and conclusionEMS interventions in nursing homes were almost never seen as necessary or indicated by emergency physicians and nurses, with the appropriate EMS level almost never being activated. The following key issues were found: shortages in numbers and competence of nursing home staff, insufficient primary care due to the unavailability of the general practitioner as well as a lack of involvement in patient care, and an absence of readily available advance directives. General practitioners should be more involved in the decision to call the Emergency Medical Services (EMS) and to transfer nursing home residents to the Emergency Department. Healthcare workers should strive for vigilance regarding the patients’ wishes. The emotional burden of deciding on an avoidable hospital admission of nursing home residents, perhaps out of fear for medico-legal consequences if doing too little, leaves the emergency physicians and nurses frustrated and disappointed. Improvements in nursing home staffing, more acute and chronic general practitioner consultations, and mobile geriatric and palliative care support teams are potential solutions. Further research should focus on the structural improvement of the above-mentioned shortcomings.

The distribution of coronavirus disease (COVID-19) cases in Japan as of March 16, 2022, showed that the highest number of patients were aged 20 to 29 years old, with a total of over one million cases. The highest number of deaths could be seen among the patients aged 80 years and older at about 15.5 thousand cases.

 Shortage of intensive care beds 

With over 1,200 hospital beds per 100,000 inhabitants available in the country, Japan is one of the best-equipped OECD nations regarding the medical sector. However, after the COVID-19 outbreak, country has faced a shortage of hospital beds, especially those required for intensive care. ICU beds only constitute a small share of the overall number of hospital beds in the country compared to European countries like Switzerland and Germany. To combat this problem, the Japanese government implemented financial incentives for hospitals upon acquisition of new intensive care beds. Another factor playing a significant part in the shortage of hospital beds is the comparably high average length of hospital stays, since some bedridden seniors are in long-term care in hospitals, as opposed to being cared for in nursing homes or at home.

Challenges for private hospitals Japan’s over eight thousand hospitals were opened by doctors, leading to the majority of the institutions being privately owned. As many of them are specialized and dependent on outpatient surgeries, COVID-19 patients pose new difficulties, as treating them in a converted ward would hinder day-to-day operations. Acquisition of intensive care beds involves financial and logistical challenges, which smaller private institutions have difficulty meeting, as they are not funded by tax revenues.

For further information about the coronavirus (COVID-19) pandemic, please visit our dedicated facts and figure page.

BackgroundThe growing number of older and oldest-old patients often present in the emergency room (ER) with undiagnosed geriatric syndromes posing them at high risk for complications in acute care.ObjectiveTo develop and validate an ER screening tool (ICEBERG) to capture 9 geriatric domains of risk in older patients.Design, setting, and participantsFor construct validity we performed a chart-based study in 129 ER patients age 70 years and older admitted to acute geriatric care (pilot 1). For criterion validity we performed a prospective study in 288 ER patients age 70 years and older admitted to acute care (pilot 2).ExposureIn both validation steps, the exposure was ICEBERG test performance below and above the median score (10, range 0–30).Outcome measures and analysisIn pilot 1, we compared the exposure with results of nine tests of the Comprehensive Geriatric Assessment (CGA). In pilot 2, we compared the exposure assessed in the ER to following length of hospital stay (LOS), one-on-one nursing care needs, in-hospital mortality, 30-day re-admission rate, and discharge to a nursing home.Main resultsMean age was 82.9 years (SD 6.7; n = 129) in pilot 1, and 81.5 years (SD 7.0; n = 288) in pilot 2. In pilot 1, scoring ≥10 was associated with significantly worse performance in 8 of 9 of the individual CGA tests. In pilot 2, scoring ≥10 resulted in longer average LOS (median 7 days, IQR 4, 11 vs. 6 days, IQR 3, 8) and higher nursing care needs (median 1,838 min, IQR 901, 4,267 vs. median 1,393 min, IQR 743, 2,390). Scoring ≥10 also increased the odds of one-on-one nursing care 2.9-fold (OR 2.86, 95%CI 1.17–6.98), and the odds of discharge to a nursing home 3.7-fold (OR 3.70, 95%CI 1.74–7.85). Further, scoring ≥10 was associated with higher in-hospital mortality and re-hospitalization rates, however not reaching statistical significance. Average time to complete the ICEBERG tool was 4.3 min (SD 1.3).ConclusionOur validation studies support construct validity of the ICEBERG tool with the CGA, and criterion validity with several clinical indicators in acute care.

Abstract

Different countries have different health outcomes that are in part due to the way respective health systems perform. Regardless of the type of health system, individuals will have health and non-health expectations in terms of how the institution responds to their needs. In many countries, however, health systems do not perform effectively and this is in part due to lack of information on health system performance, and on the different service providers.

The aim of the WHO World Health Survey is to provide empirical data to the national health information systems so that there is a better monitoring of health of the people, responsiveness of health systems and measurement of health-related parameters.

The overall aims of the survey is to examine the way populations report their health, understand how people value health states, measure the performance of health systems in relation to responsiveness and gather information on modes and extents of payment for health encounters through a nationally representative population based community survey. In addition, it addresses various areas such as health care expenditures, adult mortality, birth history, various risk factors, assessment of main chronic health conditions and the coverage of health interventions, in specific additional modules.

The objectives of the survey programme are to: 1. develop a means of providing valid, reliable and comparable information, at low cost, to supplement the information provided by routine health information systems. 2. build the evidence base necessary for policy-makers to monitor if health systems are achieving the desired goals, and to assess if additional investment in health is achieving the desired outcomes. 3. provide policy-makers with the evidence they need to adjust their policies, strategies and programmes as necessary.

Geographic coverage

The survey sampling frame must cover 100% of the country's eligible population, meaning that the entire national territory must be included. This does not mean that every province or territory need be represented in the survey sample but, rather, that all must have a chance (known probability) of being included in the survey sample.

There may be exceptional circumstances that preclude 100% national coverage. Certain areas in certain countries may be impossible to include due to reasons such as accessibility or conflict. All such exceptions must be discussed with WHO sampling experts. If any region must be excluded, it must constitute a coherent area, such as a particular province or region. For example if ¾ of region D in country X is not accessible due to war, the entire region D will be excluded from analysis.

Analysis unit

Households and individuals

Universe

The WHS will include all male and female adults (18 years of age and older) who are not out of the country during the survey period. It should be noted that this includes the population who may be institutionalized for health reasons at the time of the survey: all persons who would have fit the definition of household member at the time of their institutionalisation are included in the eligible population.

If the randomly selected individual is institutionalized short-term (e.g. a 3-day stay at a hospital) the interviewer must return to the household when the individual will have come back to interview him/her. If the randomly selected individual is institutionalized long term (e.g. has been in a nursing home the last 8 years), the interviewer must travel to that institution to interview him/her.

The target population includes any adult, male or female age 18 or over living in private households. Populations in group quarters, on military reservations, or in other non-household living arrangements will not be eligible for the study. People who are in an institution due to a health condition (such as a hospital, hospice, nursing home, home for the aged, etc.) at the time of the visit to the household are interviewed either in the institution or upon their return to their household if this is within a period of two weeks from the first visit to the household.

Kind of data

Sample survey data [ssd]

Sampling procedure

SAMPLING GUIDELINES FOR WHS

Surveys in the WHS program must employ a probability sampling design. This means that every single individual in the sampling frame has a known and non-zero chance of being selected into the survey sample. While a Single Stage Random Sample is ideal if feasible, it is recognized that most sites will carry out Multi-stage Cluster Sampling.

The WHS sampling frame should cover 100% of the eligible population in the surveyed country. This means that every eligible person in the country has a chance of being included in the survey sample. It also means that particular ethnic groups or geographical areas may not be excluded from the sampling frame.

The sample size of the WHS in each country is 5000 persons (exceptions considered on a by-country basis). An adequate number of persons must be drawn from the sampling frame to account for an estimated amount of non-response (refusal to participate, empty houses etc.). The highest estimate of potential non-response and empty households should be used to ensure that the desired sample size is reached at the end of the survey period. This is very important because if, at the end of data collection, the required sample size of 5000 has not been reached additional persons must be selected randomly into the survey sample from the sampling frame. This is both costly and technically complicated (if this situation is to occur, consult WHO sampling experts for assistance), and best avoided by proper planning before data collection begins.

All steps of sampling, including justification for stratification, cluster sizes, probabilities of selection, weights at each stage of selection, and the computer program used for randomization must be communicated to WHO

STRATIFICATION

Stratification is the process by which the population is divided into subgroups. Sampling will then be conducted separately in each subgroup. Strata or subgroups are chosen because evidence is available that they are related to the outcome (e.g. health, responsiveness, mortality, coverage etc.). The strata chosen will vary by country and reflect local conditions. Some examples of factors that can be stratified on are geography (e.g. North, Central, South), level of urbanization (e.g. urban, rural), socio-economic zones, provinces (especially if health administration is primarily under the jurisdiction of provincial authorities), or presence of health facility in area. Strata to be used must be identified by each country and the reasons for selection explicitly justified.

Stratification is strongly recommended at the first stage of sampling. Once the strata have been chosen and justified, all stages of selection will be conducted separately in each stratum. We recommend stratifying on 3-5 factors. It is optimum to have half as many strata (note the difference between stratifying variables, which may be such variables as gender, socio-economic status, province/region etc. and strata, which are the combination of variable categories, for example Male, High socio-economic status, Xingtao Province would be a stratum).

Strata should be as homogenous as possible within and as heterogeneous as possible between. This means that strata should be formulated in such a way that individuals belonging to a stratum should be as similar to each other with respect to key variables as possible and as different as possible from individuals belonging to a different stratum. This maximises the efficiency of stratification in reducing sampling variance.

MULTI-STAGE CLUSTER SELECTION

A cluster is a naturally occurring unit or grouping within the population (e.g. enumeration areas, cities, universities, provinces, hospitals etc.); it is a unit for which the administrative level has clear, nonoverlapping boundaries. Cluster sampling is useful because it avoids having to compile exhaustive lists of every single person in the population. Clusters should be as heterogeneous as possible within and as homogenous as possible between (note that this is the opposite criterion as that for strata). Clusters should be as small as possible (i.e. large administrative units such as Provinces or States are not good clusters) but not so small as to be homogenous.

In cluster sampling, a number of clusters are randomly selected from a list of clusters. Then, either all members of the chosen cluster or a random selection from among them are included in the sample. Multistage sampling is an extension of cluster sampling where a hierarchy of clusters are chosen going from larger to smaller.

In order to carry out multi-stage sampling, one needs to know only the population sizes of the sampling units. For the smallest sampling unit above the elementary unit however, a complete list of all elementary units (households) is needed; in order to be able to randomly select among all households in the TSU, a list of all those households is required. This information may be available from the most recent population census. If the last census was >3 years ago or the information furnished by it was of poor quality or unreliable, the survey staff will have the task of enumerating all households in the smallest randomly selected sampling unit. It is very important to budget for this step if it is necessary and ensure that all households are properly enumerated in order that a representative sample is obtained.

It is always best to have as many clusters in the PSU as possible. The reason for this is that the fewer the number of respondents in each PSU, the lower will be the clustering effect which